Conventionally, molds have been directly poured from a ladle into an open top of an ingot mold. Ingot molds of different shapes and sizes would be poured for different applications. For example, a wide rectangular slab mold would be used to produce rectangular ingots for sheet production and a cylindrical mold would be used to produce cylindrical ingots for tube production. Top pouring of ingot molds slowly erodes side walls of the ingot mold. Repeated erosion in an ingot side wall eventually causes an ingot to stick in an ingot mold. Upon excess sticking of an ingot within a mold, the mold must be cut open to remove the ingot. After a mold is cut open, the mold must be scrapped and replaced with a new mold.
Recently, it has been discovered that bottom pouring of ingots triples the life of a mold by greatly reducing mold erosion arising from molten metal falling against the mold wall. Bottom pouring uses a common sprue connected by ceramic conduits to bottoms of several open top ingots. The problem with bottom pouring is that ingot molds of different heights may only be filled to a height of the lowest ingot mold.
A device for controlling bottom pouring of ingots having various heights is disclosed in Japanese Patent Publication No. 56-50652 ('652). The design of the '652 publication uses a hydraulic rod to push a refractory brick in front of an ingot inlet to prevent flow to a short height ingot. The refractory brick is pushed from a hydraulically power unit located around the perimeter of a pouring area through an end wall of a ceramic conduit. The brick of the '652 design is pushed longitudinally through a central passage of the central conduit to a location that blocks flow between the conduit and an opening in an ingot. The design of the '652 publication does not appear to be useful for molds having multiple inlet gates. In addition, the hydraulic units of the '652 publication appear to be prone to damage arising from run-outs and overhead crane operators.
It is an object of this invention to produce a valve that is useful for bottom pouring ingots having multiple inlets.
It is a further object of this invention to provide an apparatus and method less prone to damage from run-outs and overhead crane operators.
It is a further object of this invention to produce a quick and flexible setup for bottom pouring open top ingot molds having different heights.